3
 Molecule – Made of more than one atom. Can be the same type or different types of atoms Element – Molecule made of Only one type of atom Compound – Molecule made of different types of atoms Particles

5
 The atomic number tells you the number of Protons (+) Electrons (-) Atomic Number Remember, the atom’s positives and negatives must equal in order for it to be balanced or neutral.

6
 Use Atomic Mass and the Atomic Number to calculate the number of neutrons an atom has: Example:Boron Atomic number – 5 Atomic mass – 10.811 1.Round the atomic mass to the nearest whole number 2. Subtract the atomic number from the rounded number Boron has neutrons in the nucleus Atomic Mass 10.811 = 11 11 – 5 = 6 6